An array substrate of an organic light-emitting diode display panel includes organic light emitting units arranged in a matrix. Each of the organic light emitting units includes an organic light-emitting diode and a thin film transistor.
FIG. 1 is a schematic sectional view showing a structure of a conventional array substrate. As shown in FIG. 1, the array substrate includes: a base substrate 1, and a thin film transistor formed on the base substrate 1. The thin film transistor includes:
a gate electrode 2, a gate insulating layer 3, an active layer 4, an interlayer insulating layer 5, a source electrode 6 and a drain electrode 7, which are sequentially formed on the base substrate 1. Via holes are formed in the interlayer insulating layer 5. As shown in FIG. 1, the via holes are filled with a portion of a conductive layer of the same material as the source electrode and the drain electrode, and the source electrode 6 and the drain electrode 7 are electrically connected to the active layer 4 through the via holes, respectively.